<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>内嵌式</title>
    <style>
        .box{
            width: 200px;
            height: 200px;
            background-color: gold;
            margin: 50px auto;
            border-radius: 50%;
            text-align: center;
            line-height: 200px;
        }
    </style>
</head>
<body>
    <div class="box">我是内嵌式</div>
</body>
</html>